File Geodatabase Where Clause for geometry filter

If you use the FeatureReader, make sure that the input feature contains a rectangular polygon that describes your bounding box. Then set the FeatureReader's spatial filter to "Envelope Intersects".

If you use the regular reader, you can use the following parameters to only read the contents of a given bounding box:

As long as your input feature class has a spatial index, the above should be very efficient.

Thank you for the quick reply @david_r . I also noticed that in FME2018.1 in the Esri Geodatabase (File Geodb Open API) Reader and the Feature Reader there is the option for setting 'SQL To Run Before Read'. Do you know if this is more efficient than using the Search Envelope as you described above?

I don't think it's possible to use "SQL to run before read" the way you describe here. That option doesn't replace a where-clause, it must be a separate, standalone SQL statement.

ah ok, so what would you use the 'SQL to run before read' to do?

Depends, but you could e.g. create a temporary index or drop a constraint and then recreate it afterwards using "SQL to run after read". The statement is not limited to the table that is read in the FeatureReader, meaning that you could also insert a log entry in a separate table. The imagination is the limit :-)